(XVII.) PNEUMOGRAPHY
Dep. of Physiology, Fac. of Medicine, MU, 2015 © Mohamed Al-Kubati
Anatomy of respiratory system
Respiratory system
• Airways
• Upper airways
• Lower airways
• Lungs
Respiratory muscles
• Inspiratory muscles
• Diaphragm
• External intercostal muscles
• Accessory inspiratory muscles
• Scalene and sternocleidomastoid
muscles
• Expiratory muscles
• Internal intercostal muscles;
abdominal muscles
Changes of intrapleural and intraalveolar pressure (related to
atmospheric pressure) during inspiration and expiration
Inspiration
• Active process – contraction of respiratory
muscles
• Decrease of intrapleural pressure
• Decrease of intraalveolar pressure
• Due to pressure gradient, air flows into lungs
Expiration
• Passive process (quiet expiration) – elasticity
of thoracic wall and lungs
• Increase of intrapleural and intraalveolar
pressure
• Air flows out of lungs
Partial pressures of gases (mm Hg) in various
parts of the respiratory system and in the circulatory system
Chemical control of breathing
Chemoreceptors
- Peripheral
- Central
- Changes of pCO2 (pH) or pO2
- Changes of activity of respiratory
neurons
Equipment
- two respiratory belts for registration of respiratory movements
- nose clip
- sterile mouthpiece
- Krogh respirometer
- PowerLab system
Procedure
Record:
- Resting respiration (1 min)
- Respiration after a mild exertion (5 squats – 10 breathing cycles)
- Respiration after an intensive exertion (30 squats – 10 BC)
- Respiration after re-breathing of the expired air from Krogh respirometer (2-3 min + recovery)
Evaluation
Following parameters in 6 chosen breathing cycles in each recorded situation
Ti - duration of inspiration
Te - duration of expiration
BI - duration of whole breathing cycle (breathing interval)
Ampl - amplitude of breathing movements
Create a table, calculate arithmetic means and standard deviations
Ampl
Ti Te BI
Statistical analysis of obtained data
Choose two sets of data which will be analyzed
Follow the procedure in textbook